I think there's a fairly reasonable concern that if he was in any sort of role with authority he couldn't be trusted to fairly deal with women.
Sure, lots of people have biases and are probably unfair. But this one wrote a NYT bestselling book where he loudly talked about his biases, and doesn't seem to have become contrite. HR complaints were very much guaranteed once this became known.
https://www.amazon.com/Asshole-Rule-Civilized-Workplace-Surv...
People don't compartmentalize anywhere near as well as some of the assumptions in this thread, and someone who is an asshole in private is going to be an asshole on the job. The "if it doesn't affect him doing his job" comments are either naive or completely disingenuous.
To repeat something I said in a not entirely dissimilar discussion: I'm not gonna let Nazis into my car club because we have a single common shared interest. They're Nazis.
I'm also not gonna work with die hard mysogynists because they're mysogynists. Great engineers who are shitty people are shitty people first and they can go right back to gutter they crawled out of.
Don't compare blemishes to prideful hate. The stupid things I've said, the hurtful things, they are not the things I want to publish and stand firm on. They are mistakes for which I feel regret. If I glorified my abhorrent behavior, you'd be right to shun me.
This guy sounds like a dick, but he doesn't sound like he's done anything wrong in this situation either. He had appropriate motivation to perform well in his position, and if Apple's human resources are worth their salt they'd be monitoring his performance very closely for the first month or two.